Fix warnings introduced in shellcheck v0.6.0

test/lint/lint-format-strings.sh

@@ -11,20 +11,20 @@
 export LC_ALL=C
 
 FUNCTION_NAMES_AND_NUMBER_OF_LEADING_ARGUMENTS=(
-    FatalError,0
-    fprintf,1
-    LogConnectFailure,1
-    LogPrint,1
-    LogPrintf,0
-    printf,0
-    snprintf,2
-    sprintf,1
-    strprintf,0
-    vfprintf,1
-    vprintf,1
-    vsnprintf,1
-    vsprintf,1
-    WalletLogPrintf,0
+    "FatalError,0"
+    "fprintf,1"
+    "LogConnectFailure,1"
+    "LogPrint,1"
+    "LogPrintf,0"
+    "printf,0"
+    "snprintf,2"
+    "sprintf,1"
+    "strprintf,0"
+    "vfprintf,1"
+    "vprintf,1"
+    "vsnprintf,1"
+    "vsprintf,1"
+    "WalletLogPrintf,0"
 )
 
 EXIT_CODE=0

test/lint/lint-whitespace.sh

@@ -23,7 +23,7 @@ while getopts "?" opt; do
 done
 
 if [ -z "${TRAVIS_COMMIT_RANGE}" ]; then
-  if [ "$1" ]; then
+  if [ -n "$1" ]; then
     TRAVIS_COMMIT_RANGE="HEAD~$1...HEAD"
   else
     TRAVIS_COMMIT_RANGE="HEAD"